Alcohol and nicotine are commonly co-abused substances. Genetic studies have provided evidence that genes influence the responses to both of these drugs independently, but more recently there have been data to suggest that common gene(s) are likely to influence responses to both drugs. There is an abundant amount of animal research providing evidence that neuronal nicotinic acetylcholine receptors, in particular 1422- containing receptors are involved in the behavioral responses to nicotine. Important for this proposal, these receptors have also been implicated in sensitivity to some effects of alcohol. Nicotinic acetylcholine receptors containing the 14 and 22 subunits have been shown to play a key role in regulating dopamine release in brain regions known to be important for underlying responses to abused drugs. This proposal focuses on the role of natural variation in these receptor subunits in alcohol and nicotine behaviors. Two samples will be used to determine if single nucleotide polymorphisms (SNPs) in the genes encoding these subunits influence sensitivity to alcohol and nicotine phenotypes. DNA and phenotypic data that have already been collected from the Colorado Center for Antisocial Drug Dependence (CADD) and the National Youth Survey (NYS) studies will be available for analysis. The candidate will examine the influence of these genes using resequencing and family-based association tests. Furthermore, the SNPs found to be associated with alcohol or nicotine behaviors will be functionally characterized using luciferase-based gene expression assays. Through this project the candidate will achieve her short-term goal of learning human statistical genetics, molecular genetics and bioinformatics tools. To learn these methods the candidate will attend coursework, symposia, workshops and conferences, in addition to having regular meeting with her mentors. All mentors of this project are faculty fellows at the Institute for Behavioral Genetics. This environment is ideal for such training because of the Institute's long history in studying questions related to the genetics of substance abuse in humans and using animal and molecular approaches. This new training will complement the candidate's prior training in mouse behavioral genetics and will be important for the candidate's long-term goal of becoming an independent researcher. With this additional training in human statistical and molecular genetics the candidate hopes to ultimately evaluate translational questions between model organism and human populations.